This procedure for determining placement sequence is typically custom-designed for each machine by the equipment
manufacturers. It is based more on the experience the manufacturer has with the machines rather than conventional
operations research techniques. Not all the machines manufactured by a manufacturer have the same algorithm. It
changes from one machine to another.
There is a built in “optimization” function on the pick and place machine used for this research. This function is used
to determine a placement order. This placement order will be created by rearranging component placements entered
from the bill of materials. The rearrangement is designed to reduce the number of nozzle replacements and to minimize
the pickup/placement path. The procedure followed in the “optimization” function for rearranging the placement data
is as follows:
1. Sorting in the order of placement layers: Rearranges the placement data in the order of layers 1, 2 and 3.
The components are placed in the order of layer 1, layer 2 and layer 3 i.e. only after all components are
placed in the lowest layer, the system can start placing on the next layer. Thus, the following optimization
rules are performed on each layer.
2. Sorting according to nozzle diameters: This sorting minimizes nozzle changes.
3. Extracting feeders which can pick up components simultaneously: Creates pairs of 2-head feeders which
can pick up components simultaneously.
4. Determining a placement sequence: Detailed information about how the actual placement sequence is
determined is not available from the manufacturer.